Preparation And Properties Of Carbon Composite Zirconia Ceramic

Zirconium oxide ceramic materials have excellent mechanical properties at room temperature,excellent high temperature and chemical corrosion resistance,and high temperature ceramic materials with wide application prospects.Due to its own brittleness and poor thermal conductivity,it limits its application to a certain great extent.Based on the excellent physical and chemical properties of multi-layer nano-graphene(GNs),the yttrium-stabilized zirconia(3Y-TZP)composite of flake graphite(FG)was studied by ball milling and stirring separation.Compared with pure zirconia(3Y-TZP)materials and direct addition of graphene composite zirconia materials,the changes of phase,microstructure,sintering properties,flexural strength and thermal conductivity of high temperature calcination were studied.As the results show:(1)After calcination at high temperature,there is no changeable phase transition in different carbon composite zirconia ceramics,that is to say,the original tetragonal stable crystal structure is still maintained.For the flake graphite composite zirconia material treated by the ball mill-stirring separation process,the micro-morphology of the flaky graphite coated on the zirconia surface becomes thinner and thinner,similar to graphene(GNs),and is firmly bonded to the zirconia particles without falling off..(2)Compared with pure 3Y-TZP samples,the compactness of different carbon composite zirconia ceramics after calcination at high temperature has been improved to some extent,and the density of 0.5wt%GNs/3Y-TZP samples sintered at 1650? is the best,up to 96%.For ball milling-flotation treated 1.0wt%FG/3Y-TZP samples,the best densification is 94% after calcination at 1650?.But pure 3Y-TZP relative density is only 90% after 1650? calcination.It shows that different carbon materials and the introduction of flotation technology can make zirconia composites more densification.(3)The flexural strength and thermal conductivity of the composite zirconia ceramics with different carbon materials after calcination are better than those of pure 3Y-TZP,in which the flexural strength and thermal conductivity of 0.75wt% GNs/3Y-TZP materials after calcination at 1650°C The increase of 110% and 30% respectively for the 1.5wt% FG/3Y-TZP material after ball milling-stirring separation is increased by 100% and 25% after calcination at 1650°C;different carbon materials The fracture curves of the composite zirconia ceramic materials show slight fluctuations,which are intuitively different from the pure 3Y-TZP cliff-type curves,and the comprehensive performance of the FG/3Y-TZP materials after agitation separation is close to GNs/3Y.-TZP.